My new scope - Skywatcher MN190 Mk1

[Sirius Bizness]

I have been trying to resist extra aperture ever since getting into this hobby but my ED80 turned into a 120ED and now I have ended up cracking again and getting a SW Mak Newt 190. The reason I went for this was the imaging potential and the fact it is a closed tube (I don’t like the idea of the mirror being open to the elements).

I picked up the MN190 (Mk1 version) second hand for a reasonable price. It looks in mint condition and if the dovetail is anything to go by its only been used a handful of times. I am glad I saved a few pounds and went with the mk1 version as my experience of any SW focuser is they are all not very good. I can now put the money towards an upgrade focuser when needed .

I knew they were heavy but I think this is pushing it for the HEQ5. First problem is I don’t have enough counterweight so cant balance the scope! My initial use of this scope will be for visual as being new to the hobby I am still learning the sky and can’t get my eye away from the eyepiece. I can’t wait to have a look a M13 and trying to bag my first galaxy (M31 not visible from my garden).

I am still trying to get my head around this type of scope and understanding how to use it. It feels alien and a lot more complicated than my refractors. I have a few questions and am hoping some of you could help answer them.

As the scope is second hand I am not sure what is meant to be like what. I think the scope must be one of the first available as it has the single speed Crayford and has black ends/rings whereas all the DS Pro versions are white. Were there any other differences other than the focuser and colour?

First thing I noticed was a large flat (kink) running all the way down the tube. Is this normal? I know the tube has to be fabricated from sheet but are they all like this (I know its a Skywatcher)?

I know nothing about collimation and have only just worked out I need a Cheshire collimating EP. I can see a ring in the centre of the primary which I guess is for collimation. There is also a small ring on what I believe is called the secondary mirror. It doesn’t look perfectly round and appears hand drawn. Do all MN190s have this on the secondary? I have taken a photo.

I know how to check collimation on a star so will have a look first before adjusting anything. I understand the primary mirror is collimated using the Phillips screws and grub screws. Is there a guide anywhere on how to adjust? What are the little knobs for? I don’t get why these scopes don’t come with user manuals .

This one might sound stupid but what orientation should the focuser on the OTA be when loaded on the mount? Is there a specific starting orientation which works best?

Before any use I need extra counterweight. What have other done for this…just an extra 5KG counterweight? I was looking at the extension bar or a heavier weight. I think this setup will work ok on the HEQ5 for visual but not so sure for imaging.

Also I understand Dew can be a problem on the corrector plate. The scope came with a dew shield. Will I need a heater strip as well or will the shield be enough?

Any info from users of the same setup or anyone who can answer any of the above would be greatly appreciated.

Thanks, Martin

[Nibor]

Martin,

For collimation help there is loads of info on SGL and the internet - for starters try....

http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm

I have just aquired my first newtonian and it has been a bit of a steep learning curve - take it steady - plenty of cups of coffee - do what you can in daylight and enjoy the learning experience!!!

It looks like a decent aquisition "Schott" glass logo - so its fairly new I would think.

See if you can find the manual on:-

http://www.skywatcher.com/swtinc/customer_support.php?id=71&class1=1&class2=130

Hope this helps.

[Sirius Bizness]

Nibor, thanks for pointing me in the direction of that very useful info on collimation. No user guide for a Mak Newt tho.

As you said just take it slow and that's is what I did tonight.

Got an extra 5kg weight and they are all at max extension to balance with heavy EPs. The HEQ5 is groaning! Got it all balanced nicely and went for a first session.

Wow the views were incredible. Did a tour of the classic bright objects I have been getting familiar with and M13 was well resolved. Amazing. Definately an improvement over the 120ED. And to think it only cost half of what the 120ED did both second hand.

On thing to sort is the focus extensions. The focuser only has 50mm of travel and using the 50mm extension to achieve focus I had problems when I got to the 12mm Nagler. I had to slide the extension tube out another 10mm to achieve focus which didn't feel right.

Collimation on a star test looks perfect straight out the box. One reason I went for the Mak Newt over a Newt or Dob was the reputation for holding collimation. Seems to be true so far.

Cant wait to try some more objects and hopefully bag my first galaxy!

[John]

Sounds a great scope

I used to have a Russian (Intes) 6" mak-newtonian and the views through it were really excellent. I guess the extra aperture of the 190 will deliver even more. Collimation was a bit tricky on my mak-newt but once done (I used the star test method rather than a laser or cheshire eyepiece) it held collimation very well.

The only drawbacks I found with my 6" MN was that it was heavy and the cool down time on the colder nights was quite long to get it fully cooled.

Nice scopes though and very versatile

[Gunnar]

Hi.

I have this large flat (kink) running all the way down the tube on mine too and I also have the small ring on the secondary

See this "little bit old" thread started by me. Maybe something there to help you.. sorry for my bad spelling

http://stargazerslounge.com/topic/141012-skywatcher-190mn-fitting-of-a-moonlite-focuser/page__hl__%20fitting%20%20of%20%20moonlite

Manual here. http://www.telescope...29370_07-09.pdf

Gunnar

[Gunnar]

Hi.

I have this large flat (kink) running all the way down the tube on mine too and I also have the small ring on the secondary

See this "little bit old" thread started by me. Maybe something there to help you.. sorry for my bad spelling

http://stargazerslou...g of moonlite

Manual here. http://www.telescope...29370_07-09.pdf

Gunnar

Manual http://www.telescope...29370_07-09.pdf